The invention relates to a device for monitoring the area, region or range of a robot, monitoring taking place of at least one area of a rotary movement about at least one robot axis.
Hitherto for the area monitoring of robot axes use has been made of conventional methods with components which involve contact, such as in particular mechanical cam switches. Such cam switches and associated evaluations are complicated and costly. In addition, such components are subject to high wear, so that there is a high monitoring and replacement need. In addition, they are also subject to malfunctions. In the case of such a monitoring with mechanical switches and relays with forcibly guided contacts it is not possible achieve a desirable electronic programmability and variability of the areas to be monitored.
Therefore the problem of the invention is to provide an area monitoring in which the aforementioned disadvantages are overcome.
In the case of device in the aforementioned type, the problem is inventively solved in that initiators or switches cooperating with part annular cams positoned coaxially to the axis being monitored are provided and the initiators are connected to an evaluating device.
Thus, for solving the problem the invention provides for the use of electronic initiators, such as in particular electronic proximity switches, which are connected to an evaluating device. In an extremely preferred development with each area to be monitored, consisting of a release or working area and a danger area, there are at least two independently operating initiators so that high security and safety are obtained. The two initiators can be permanently monitored with respect to their functional efficiency by the evaluating device. The invention provides for an area monitoring for robot axes with a secure and safe technology by means of which the axis-related movement areas for the individual robots can be blocked in order to protect persons and material. However, the device according to the invention suffers the high demands made on the safety of monitoring circles for personnel protection.
In a preferred further development, grooved strips arranged coaxially to the axis about which a movement is monitored are connected to cams and that with each cam is associated an initiator.
According to a further development with an area to be monitored is associated an initiator operating as an opener and an initiator operating as a closer. In a preferred development a danger area of a monitoring area is protected by an initiator operating as an opener and/or a release area of a monitoring area is protected by an initiator operating as a closer. A preferred combination of the aforementioned construction is characterized in that an initiator operating as an opener is associated with a cam corresponding to a danger area and an initiator operating as a closer is associated with a cam corresponding to a release area for the same area to be monitored.
According to further developments of the invention the cams are retained by two-part cam end pieces, whose lower part is positively retained in the grooved strip in radial movement and whose upper part is connected to the lower part and the lower and upper parts can be braced against one another for non-positive fixing on the grooved strip and also braced against the latter.
In another development according to the invention a cam is fixed between two cam end pieces and it can also be provided that a cam is connected to the cam end pieces by threaded pins.
Another preferred construction of the invention is characterised in that the initiators are adjustable and fixable relative to the cams associated therewith both radially and in elevation parallel to the axis with respect to which the cams are coaxially arranged. In a further development there is an at least two-channel monitoring for each area to be monitored.
Finally, according to the invention, there can be a combination of an area monitoring of the movement of the robot and an access monitoring with respect to the robot.